Because the damage to the ozone layer has become a problem in recent years, the use of HCFCs as refrigerants has recently begun to be reduced as a step toward the goal of their complete elimination. Hereafter, the gradual reduction of HCFC type refrigerants (HCFC-22 and the like) will continue worldwide, and it will be necessary instead to use substitute refrigerants such as HFC type refrigerants and the like.
In this situation, there are an increasing number of cases in which previously installed refrigerant using equipment (such as air conditioners and the like) is modified in order to use a substitute refrigerant.
In addition, with multi-type air conditioners that are installed inside structures such as apartment buildings, office buildings, and the like, and with air conditioners that air condition the entire space inside a residential home (housing air conditioners), the refrigerant lines that connect the outdoor unit with the indoor units are embedded in the walls or extend over the rear surface of the ceiling. In this type of situation, in order to dismantle the preexisting air conditioner and install a new air conditioner, whether or not the preexisting refrigerant lines can be appropriated (reused) with the new air conditioner is an important factor in the cost of installation. This is because the task of replacing the preexisting lines will take a great deal of time and cost a great deal of money. In addition, even if the preexisting lines can be appropriated, whether or not it will be necessary to clean the preexisting lines will be a factor in reducing the installation costs.
Generally, refrigerator oil that contains impurities will remain adhered to the preexisting lines. If the fouling from the remaining oil is severe, there is a strong possibility that the remaining impurities will infiltrate the new refrigerant to be used, the decompressor that is the expansion mechanism (an expansion valve or a capillary tube) will become clogged and will cease operating, and the refrigerant oil will deteriorate. In particular, refrigerant oils that are used with HFC type refrigerants are synthetic oils such as ether oil or ester oil, and easily dissolve the impurities in the preexisting lines because of their high polarity. Thus, when using HFC type refrigerants in new air conditioners, there is a strong possibility that problems may occur in the decompressor of the new air conditioner due to the remaining impurities in the preexisting lines.
Thus at present, a cleaner will be employed to clean the interior of the lines when one attempts to appropriate preexisting lines that have been used for 10–20 years.
However, a cleaner that cleans preexisting lines is extremely expensive, and moreover, the cost of cleaning is not cheap.
On the other hand, cleaning is not necessary when there is little fouling of the preexisting lines. There are also cases in which the fouling of the preexisting lines will be reduced, and the need for cleaning will be eliminated, due to the method by which the refrigerant and the oil are recovered.
However, obtaining a sample of the residual material inside the preexisting lines, bringing it to a research lab or the like, and examining the oil or refrigerant in the preexisting lines has, in the past, cost more than the cost of cleaning. Because of this, manufacturers currently unconditionally recommend in most cases that the preexisting lines be cleaned with a cleaning device.
When there is no need for cleaning, it is preferable that the preexisting refrigerant lines (preexisting lines) be reused as is.
In addition, it is preferable that uninstalled refrigerant using equipment be reused to the greatest extent possible due to environmental concerns. Preexisting equipment includes that which can be reused if cleaned, and that which can be reused if some of the components thereof (such as the compressor and the like) are replaced.